Lithium-ion secondary cells include a positive electrode, a negative electrode and a liquid electrolyte which intermediates the electrodes and are charged and discharged by transfer of lithium ions between the positive and negative electrodes via the liquid electrolyte containing an electrolyte component such as a lithium salt. Typical negative electrodes in this type of lithium-ion secondary cells contain a negative electrode active material which can reversibly store and release lithium ions. The negative electrode active material is mainly various carbon materials such as graphite materials. Graphite has a laminar crystalline structure and allows charge and discharge by storing lithium ions to interlayers and releasing lithium ions from interlayers.
When a current collector is coated with a composition prepared in a paste-like form containing graphite as a negative electrode active material (the paste composition includes a slurry composition and an ink composition; hereinafter the paste composition is merely referred to as “composition”) to form a negative electrode, graphite tends to be arranged such that the layers of graphite ((002) planes) are parallel to the surface (plane having a broader width) of the current collector. Therefore edge parts (edges of multiple layers) of graphite may be arranged approximately parallel to the current collector, and storaging lithium ions to interlayers and releasing lithium ions from interlayers may not be smoothly carried out during charge and discharge. Patent Literature 1 may be mentioned as the conventional art that sought to address such a problem. Patent Literature 1 discloses a technique for arranging layers of graphite so as to be perpendicular to a current collector by applying a magnetic field to a composition. In addition, Patent Literature 2 may be mentioned as the conventional art relating to the negative electrode of lithium-ion secondary cells.